High Dose Methotrexate followed by citrovorum factor "rescue" has been administered to patients with refractory lymphoma and advanced sarcoma. In order to decrease toxicity, bicarbonate is administed orally and urinary pH is monitored. Radioimmunoassay for methotrexate has been used and will hopefully be of assistance in regulating dosage in the future. To date, 2 patients with advanced lymphoma have been treated and neither have responded to therapy. There have been no objective responses in patients with metastatic soft tissue sarcomas.